Conventionally, there are known compact disks (hereinafter called CD) as a disc shaped recording medium wherein pieces of information such as music programs are recorded by converting them into digital signals.
These CD's are used only for reproduction, and for those used for music programs, a plurality of music programs are successively recorded on the disk. At the innermost track, what we call a lead-in area thereof, there is created a so-called TOC (Table Of Content) area wherein for example recording start positions with respect to each music program are recorded.
When a CD is placed into a reproducing device for reproduction, information recorded in the TOC area is first reproduced, and then by the information, the number of music programs, recording start time (position) for example, and the of each program, recorded in the CD placed therein, are recognized, and in the reproducing operations thereafter, an access to any music program is performed in short time by using the information recorded in the TOC area.
In the meantime, since those CD's are used only for reproduction, as a new method, it has been desired to develop a disk recording and reproducing device whereby the user can freely record for example music programs on a recording medium. In that case, as the recording medium, it is suggested to apply magneto-optical disks or the like functioning as a re-writable recording medium. Moreover, the disk recording and reproducing device is preferably designed to have an interchangeability so that it can also reproduce conventional CD's.
As to a recording method in the above arrangement, in order to perform CLV (Constant Linear Velocity) control to the disk, which is executed in the conventional CD's, it is suggested that grooves wobbling according to values of absolute addresses or pits indicating absolute addresses are formed on the disk when it was fabricated, and that, in recording information thereon, accesses to unrecorded parts and the CLV control are performed by using the above absolute addresses, and the same signal formats as those in the conventional CD's are employed.
Furthermore, in the above re-writable disk, at the time when a recording operation for each music program has been finished, the absolute addresses indicating the recording start position and recording end position thereof are successively recorded in the TOC area while corresponding those absolute addresses to the program numbers, and in the reproductions thereafter the absolute addresses recorded therein are of great use.
In that case, when a piece of information recorded in an information recording area is rewritten, it is necessary to replace the contents of the TOC area according to the change.
For example, as shown by (a) in FIG. 23, when music programs from the first program M1 to fourth program M4 are recorded in the information recording area, as shown in Table 1, the program number and the recording start position as well as recording end position for each of the music programs M1 to M4 are recorded as additional information.
TABLE 1 ______________________________________ Recording Start Recording End Program No. Position Position ______________________________________ 01 (00'00") (08'37") 02 (08'40") (23'12") 03 (23'16") (39'41") 04 (39'48") (55'30") ______________________________________
Next, as shown by (b) in FIG. 23, in the case where another music program M2' is newly recorded in an area wherein the second program M2 has already been recorded, if the latter half of the second program M2 remaining after the recording end position of the M2' is considered to be unnecessary information, it is only necessary to rewrite additional information with respect to the second program in the contents of the TOC area, as shown in Table 2.
TABLE 2 ______________________________________ Recording Start Recording End Program No. Position Position ______________________________________ 01 (00'00") (08'37") 02 (08'40") (14'56") 03 (23'16") (39'41") 04 (39'48") (55'30") ______________________________________
However, as shown by (c) in FIG. 23, in the case where another music program M2' is recorded in the area wherein the second program M2 has been recorded, when M2' is longer than the former second program M2, the former third program M3 is partially erased. In that case, if the remaining part of the former third program M3 is considered to be unnecessary information, the contents of the TOC area are replaced as shown in Table 3. More specifically, on the one hand, additional information with respect to the second program is rewritten, and on the other hand, the program number is changed and the former fourth program is moved up to be the third program. Accordingly, in that case, in order to rewrite the information in the TOC area, at least, pieces of information shown by the program numbers "02" and "03" in Table 1 should be rewritten into pieces of information shown by the program numbers "02" and "03" in Table 3, and a piece of information shown by "04" in Table 1 should be erased. When this method is adapted to a case where, for example, there are program numbers from "01" to "30", it requires a lot of time to rewrite the information recorded in the TOC area.
TABLE 3 ______________________________________ Recording Start Recording End Program No. Position Position ______________________________________ 01 (00'00") (08'37") 02 (08'40") (32'09") 03 (39'48") (55'30") ______________________________________
Moreover, as to the capacity of the TOC area, it is suggested to give a capacity requiring, for example, several tens of second in reproduction, however, in the case where the disk recording .and reproducing device is designed to reproduce information in all the TOC area when the disk is placed therein, reproducing time for all the capacity of the TOC area is required even if actual additional information recorded therein is very little compared with the capacity of the TOC area, and therefore a problem arises in that waiting time required to reach a stand-by state is very long.
Furthermore, in the aforementioned disk recording and reproducing device, for example, in recording music programs recorded on another recording medium as a music source, it is possible for the user himself to instruct to start a recording operation through operation keys by choosing a right timing while listening to the music program coming from the music source.
However, in the recording operations for such music programs, the leading part of the music program is sometimes not recorded due to wrong timing in starting the recording operation, and the user suspends the operation halfway when he notices the wrong timing, and then he resumes the recording operation. In that case, it is suggested that, in order to start a recording to be resumed from a position conforming to the start position of the former music program (the music program having been failed in recording), an absolute address indicating the start position is predeterminately stored, and that, in resuming the recording operation, the recording is operated after returning to the position indicated by the absolute address.
More concretely, as shown in FIG. 24, assuming that the recording of the music program having been failed in recording is started from a position shown by F in the figure on a track 59 formed in a spiral state (the recorded part is shown by hatching in the figure), in resuming the recording operation, after accessing an optical head to a position indicated by an absolute address F' of the recording start position predeterminately stored, it is kept in a stand-by state while being permitted to make a track-jump to the inner track every rotation of the disk. In this case, assuming that the track-jump is made from a position G to a position G' in the figure, the route of a light spot is expressed by a loop shown in an alternate long and short dash line in the figure. Therefore, as shown in FIG. 25, signals contained within the section traced back by one rotation are repeatedly reproduced.
However, if the user operates the operation keys at his will during the aforementioned stand-by state, as shown in FIG. 26, the recording operation is sometimes performed from a position H located away past the recording start position F of the former music program. In other words, within the section tracked by one rotation during the aforementioned stand-by state, there is contained a recording area of the former music program, that is, a range shown by F to G, and it is possible that a recording of a new music program is started from H within the range.
In the case above-mentioned, there remains the former music program located in the section F to H. As a result, in reproduction, the leading part of the former music program is reproduced, although it might be a short period of time, thereby presenting a problem in that the quality of the music program is affected.
In the meantime, when there are scratches or the like on a magneto-optical disk caused when it was fabricated or due to ill usage by the user, malfunction might arise in recording or reproducing music information or the like thereon or therefrom. Especially in the case of recording successive information of music or the like, even a defect in a part of the disk might cause interruption of the recording from the point on, and might also cause damage on the information already stored in the other areas. Further, in the case of re-writable disks such as magneto-optical disks, the above problems might occur every time a rewriting operation is performed on the disk.
To deal with such problems, at present, only we can do is to stop using the disk even if it has a defect only in a part thereof, or to find the defective part and avoid using the defective area in recording by making a note for ourselves to recognize where the defective area is located.
Moreover, in the case where a copying (analog copying) operation for music information is performed from the disk recording and reproducing device to an external recording device, as with the conventional method, the user has to determine a reproducing level and a recording level at the disk recording and reproducing device as a reproducing device and at the external device as a recording device while examining level meters or the like.
In performing such copying operations, generally, it is necessary to determine the levels of reproduction and recording so that the value of the peak level of the reproduction can be settled within a permissible range of the recording level of the external recording device. However, since the determination of the levels must be made while monitoring a peak level only appearing momentarily, those operations are difficult as well as troublesome for the user.
In the meantime, when it is permitted for the user to freely record his desired music programs or the like, he may want to preserve his specially favorite and important music programs as long as he likes, and therefore for such demands it is suggested to give write protection to every disk.
However, to give write protection to every disk means to perform write protection uniformly over the whole information recorded in a disk, and therefore it is not possible to give write protection to each of music programs respectively. Consequently, in this system it is not possible to erase or rewrite unnecessary music programs with necessary music programs kept remaining in the disk, and the system has a drawback in that advantages of re-writable disk are not fully exhibited. The drawback is common in the case where the information is ordinary data or the like, not being limited to the music programs (music information).
One of the objects of the present invention is to solve the above problem; however, by the use of the invention, when write protection is applied to each music program, and then a new music program is recorded in a non-write-protection range, there arises a case where the capacity of the non-write-protection range (range where write protection is not applied) is smaller than the capacity required to record the new music program therein. Therefore, in reproducing from the disk wherein such recordings are made, the performance of the newly recorded music program is finished halfway, and simultaneously with the finishing, the performance of the music program recorded in a write protection range is started. Consequently, a drawback is presented in that the listener feels displeased because of having a missing part at the end of the music program.
Furthermore, besides the above, the following various demands are presented when the user wants to record on a disk music information of his own make. It is a demand to keep secrecy from others about the recorded information. Since the information with respect to the above demand for secrecy is mostly very important, it is another demand to keep the important information from being erased due to ill operation by others. It is a further demand to avoid making high-quality copies although the demand for secrecy is not asked so strictly. Therefore, by adding functions to meet the above demands, the present invention aims at providing a disk recording and reproducing device having full functions.